程序代码：

/*
    随机生成M个同学3个科目的成绩，范围在40~100（含）
    统计每个同学的平均分和每个科目的平均分
    将同学按总分（平均分）由高到低排列
    输出特定格式的报表
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>

/*M必须大于1*/
#define M 5
#define N 5

void input(int scores[][3]);
void cal(int scores[][3], double avgR[], double avgC[]);
void sort(double avgR[], int idx[]);

int main(void)
{
    char *ke[N] = {"语文","数学","英语","平均分","总分"};
    char *names[M] = {"张三", "李四", "王五", "赵六", "田七"};
    int scores[M][3] = {0}, idx[M] = {0}, i, j;
    double avgR[M] = {0}, avgC[3] = {0};
    input(scores);
    cal(scores, avgR, avgC);
    sort(avgR, idx);
    for(j=0;j<N;j++)
    {
        printf("    %8s", ke[j]);
   
    }
    for (i = 0; i < M; i++)
    {
        printf("%8s", names[i]);
        for (j = 0; j < 3; j++)
        {
            printf("%4d  ", scores[i][j]);
        }
        printf("%5.1lf\n", avgR[i]);
    }

    return 0;
}

void input(int score[][3])
{
    int i, j;
    for (i = 0; i < M; i++)
        for (j = 0; j < 3; j++)
            score[i][j] = 40 + rand() % 61;
    return;
}
void cal(int scores[][3], double avgR[], double avgC[])
{
    int i, j;
    for (i = 0; i < M; i++)
    {
        for (j = 0; j < 3; j++)
        {
            avgR[i] += scores[i][j];
            avgC[j] += scores[i][j];
        }
        avgR[i] /= 3;
    }
    for (j = 0; j < 3; j++)
        avgC[j] /= M;
    return;
}
void sort(double avgR[], int idx[])
{
    int i, j;
    for (i = 0; i < M; i++)
        idx[i] = i;
    for (i = 0; i < M - 1; i++)
    {
        for (j = i + 1; j < M; j++)
            if (avgR[i] < avgR[j])
                idx[i] = j, idx[j] = i;
    }
    return;
}